Depending on what I'm doing to the boat, i.e. when running it for draining the oil, I take the sea strainer off, wrap a rag around a heavy duty garden hose, and stuff it into the hose that the outlet of the strainer goes into. It's good because you can let it leak a bit, I've seen that hose inflate like a balloon on boats where the hose was connected with a tight connection:) Turn the hose on and warm the boat up with hose water.
If you just want to winterize, pull the thermostat (3x12mm nuts) and bolt the housing back up. Hook a large funnel to the inlet hose and pour the fluid in while running until its leaking out the exhaust flaps. Run the shower pump if you have one. Heater core will fill automatically w/fluid. Shut engine off and replace thermostat. Make sure .125" hole in tstat is at 1200, so air will burp out of the housing when you are running.
USE ENVIRONMENTALLY SAFE ANTIFREEZE:00 It's gonna end up in the lake or in the ground water.
THAT being said, I just drain my block and manifolds and heater and shower and oil and trans cooler. Hmm, the antifreeze method might be better, with a V drive situation. I usually run my boat during the winter, but the lake is DOWN this year.
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